Parlay (gambling) – Wikipedia
A parlay, accumulator, combo bet or multipurpose is a single bet that links together two or more individual wagers and is dependent on all those wagers winning together. The benefit of this parlay is that there are far higher payoffs than placing each individual bet separately, since the problem of hitting all of them is higher. If some of the bets in the parlay shed, the whole parlay loses. If any of the plays at the parlay ties, or”pushes”, the parlay reverts to a lesser number of teams together with the odds reducing accordingly.
Parlay bets are paid out at odds higher than the normal single game wager, but still under the”true” odds. For instance, a common 2-team NFL parlay based completely on the distribute normally has a payout of 2.6:1 if the two picks are right. [citation needed] In fact, however, if one supposes that every single match wager is a coin flip and could be expected to pay out at 1:1, the genuine payout must instead be 3:1, a substantial gap.
The house makes a 20-31% gain on spread parlays, compared to a 7 percent gain on individualized sports stakes. [2]
An alternate way to do a parlay is to wager on at least two favorites simply winning straight up. In order to calculate the payout of this parlay, an individual must multiply the payout for all 3 games. For instance, if 3 teams are all +385 favorites, then a prosperous parlay on all 3 groups winning would pay out in a ratio of approximately 1/1. This is because (385/485)^3 is approximately 50 percent
Read more here: http://jikoobelt.com/adv03/?p=14202